user/sven/linux.git/kernel/debug/kdb, branch v4.14.258

kdb: Make memory allocations more robust

2021-03-03T17:22:36Z

commit 93f7a6d818deef69d0ba652d46bae6fbabbf365c upstream. Currently kdb uses in_interrupt() to determine whether its library code has been called from the kgdb trap handler or from a saner calling context such as driver init. This approach is broken because in_interrupt() alone isn't able to determine kgdb trap handler entry from normal task context. This can happen during normal use of basic features such as breakpoints and can also be trivially reproduced using: echo g > /proc/sysrq-trigger We can improve this by adding check for in_dbg_master() instead which explicitly determines if we are running in debugger context. Cc: stable@vger.kernel.org Signed-off-by: Sumit Garg Link: https://lore.kernel.org/r/1611313556-4004-1-git-send-email-sumit.garg@linaro.org Signed-off-by: Daniel Thompson Signed-off-by: Greg Kroah-Hartman

kdb: Fix pager search for multi-line strings

2020-10-29T08:07:10Z

[ Upstream commit d081a6e353168f15e63eb9e9334757f20343319f ] Currently using forward search doesn't handle multi-line strings correctly. The search routine replaces line breaks with \0 during the search and, for regular searches ("help | grep Common\n"), there is code after the line has been discarded or printed to replace the break character. However during a pager search ("help\n" followed by "/Common\n") when the string is matched we will immediately return to normal output and the code that should restore the \n becomes unreachable. Fix this by restoring the replaced character when we disable the search mode and update the comment accordingly. Fixes: fb6daa7520f9d ("kdb: Provide forward search at more prompt") Link: https://lore.kernel.org/r/20200909141708.338273-1-daniel.thompson@linaro.org Reviewed-by: Douglas Anderson Signed-off-by: Daniel Thompson Signed-off-by: Sasha Levin

kdb: do a sanity check on the cpu in kdb_per_cpu()

2020-01-27T13:46:34Z

[ Upstream commit b586627e10f57ee3aa8f0cfab0d6f7dc4ae63760 ] The "whichcpu" comes from argv[3]. The cpu_online() macro looks up the cpu in a bitmap of online cpus, but if the value is too high then it could read beyond the end of the bitmap and possibly Oops. Fixes: 5d5314d6795f ("kdb: core for kgdb back end (1 of 2)") Signed-off-by: Dan Carpenter Reviewed-by: Douglas Anderson Signed-off-by: Daniel Thompson Signed-off-by: Sasha Levin

kdb: Don't back trace on a cpu that didn't round up

2019-02-12T18:46:09Z

[ Upstream commit 162bc7f5afd75b72acbe3c5f3488ef7e64a3fe36 ] If you have a CPU that fails to round up and then run 'btc' you'll end up crashing in kdb becaue we dereferenced NULL. Let's add a check. It's wise to also set the task to NULL when leaving the debugger so that if we fail to round up on a later entry into the debugger we won't backtrace a stale task. Signed-off-by: Douglas Anderson Acked-by: Daniel Thompson Signed-off-by: Daniel Thompson Signed-off-by: Sasha Levin

kdb: use memmove instead of overlapping memcpy

2018-12-08T12:03:36Z

commit 2cf2f0d5b91fd1b06a6ae260462fc7945ea84add upstream. gcc discovered that the memcpy() arguments in kdbnearsym() overlap, so we should really use memmove(), which is defined to handle that correctly: In function 'memcpy', inlined from 'kdbnearsym' at /git/arm-soc/kernel/debug/kdb/kdb_support.c:132:4: /git/arm-soc/include/linux/string.h:353:9: error: '__builtin_memcpy' accessing 792 bytes at offsets 0 and 8 overlaps 784 bytes at offset 8 [-Werror=restrict] return __builtin_memcpy(p, q, size); Signed-off-by: Arnd Bergmann Signed-off-by: Jason Wessel Signed-off-by: Greg Kroah-Hartman

kdb: Use strscpy with destination buffer size

2018-12-01T08:42:54Z

[ Upstream commit c2b94c72d93d0929f48157eef128c4f9d2e603ce ] gcc 8.1.0 warns with: kernel/debug/kdb/kdb_support.c: In function ‘kallsyms_symbol_next’: kernel/debug/kdb/kdb_support.c:239:4: warning: ‘strncpy’ specified bound depends on the length of the source argument [-Wstringop-overflow=] strncpy(prefix_name, name, strlen(name)+1); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ kernel/debug/kdb/kdb_support.c:239:31: note: length computed here Use strscpy() with the destination buffer size, and use ellipses when displaying truncated symbols. v2: Use strscpy() Signed-off-by: Prarit Bhargava Cc: Jonathan Toppins Cc: Jason Wessel Cc: Daniel Thompson Cc: kgdb-bugreport@lists.sourceforge.net Reviewed-by: Daniel Thompson Signed-off-by: Daniel Thompson Signed-off-by: Sasha Levin

kdb: print real address of pointers instead of hashed addresses

2018-11-21T08:24:14Z

commit 568fb6f42ac6851320adaea25f8f1b94de14e40a upstream. Since commit ad67b74d2469 ("printk: hash addresses printed with %p"), all pointers printed with %p are printed with hashed addresses instead of real addresses in order to avoid leaking addresses in dmesg and syslog. But this applies to kdb too, with is unfortunate: Entering kdb (current=0x(ptrval), pid 329) due to Keyboard Entry kdb> ps 15 sleeping system daemon (state M) processes suppressed, use 'ps A' to see all. Task Addr Pid Parent [*] cpu State Thread Command 0x(ptrval) 329 328 1 0 R 0x(ptrval) *sh 0x(ptrval) 1 0 0 0 S 0x(ptrval) init 0x(ptrval) 3 2 0 0 D 0x(ptrval) rcu_gp 0x(ptrval) 4 2 0 0 D 0x(ptrval) rcu_par_gp 0x(ptrval) 5 2 0 0 D 0x(ptrval) kworker/0:0 0x(ptrval) 6 2 0 0 D 0x(ptrval) kworker/0:0H 0x(ptrval) 7 2 0 0 D 0x(ptrval) kworker/u2:0 0x(ptrval) 8 2 0 0 D 0x(ptrval) mm_percpu_wq 0x(ptrval) 10 2 0 0 D 0x(ptrval) rcu_preempt The whole purpose of kdb is to debug, and for debugging real addresses need to be known. In addition, data displayed by kdb doesn't go into dmesg. This patch replaces all %p by %px in kdb in order to display real addresses. Fixes: ad67b74d2469 ("printk: hash addresses printed with %p") Cc: Signed-off-by: Christophe Leroy Signed-off-by: Daniel Thompson Signed-off-by: Greg Kroah-Hartman

kdb: use correct pointer when 'btc' calls 'btt'

2018-11-21T08:24:14Z

commit dded2e159208a9edc21dd5c5f583afa28d378d39 upstream. On a powerpc 8xx, 'btc' fails as follows: Entering kdb (current=0x(ptrval), pid 282) due to Keyboard Entry kdb> btc btc: cpu status: Currently on cpu 0 Available cpus: 0 kdb_getarea: Bad address 0x0 when booting the kernel with 'debug_boot_weak_hash', it fails as well Entering kdb (current=0xba99ad80, pid 284) due to Keyboard Entry kdb> btc btc: cpu status: Currently on cpu 0 Available cpus: 0 kdb_getarea: Bad address 0xba99ad80 On other platforms, Oopses have been observed too, see https://github.com/linuxppc/linux/issues/139 This is due to btc calling 'btt' with %p pointer as an argument. This patch replaces %p by %px to get the real pointer value as expected by 'btt' Fixes: ad67b74d2469 ("printk: hash addresses printed with %p") Cc: Signed-off-by: Christophe Leroy Reviewed-by: Daniel Thompson Signed-off-by: Daniel Thompson Signed-off-by: Greg Kroah-Hartman

kdb: make "mdr" command repeat

2018-05-30T05:52:41Z

[ Upstream commit 1e0ce03bf142454f38a5fc050bf4fd698d2d36d8 ] The "mdr" command should repeat (continue) when only Enter/Return is pressed, so make it do so. Signed-off-by: Randy Dunlap Cc: Daniel Thompson Cc: Jason Wessel Cc: kgdb-bugreport@lists.sourceforge.net Signed-off-by: Jason Wessel Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

kdb: Fix handling of kallsyms_symbol_next() return value

2017-12-14T08:52:58Z

commit c07d35338081d107e57cf37572d8cc931a8e32e2 upstream. kallsyms_symbol_next() returns a boolean (true on success). Currently kdb_read() tests the return value with an inequality that unconditionally evaluates to true. This is fixed in the obvious way and, since the conditional branch is supposed to be unreachable, we also add a WARN_ON(). Reported-by: Dan Carpenter Signed-off-by: Daniel Thompson Signed-off-by: Jason Wessel Signed-off-by: Greg Kroah-Hartman